Vitamin A reduces lung granulomatous inflammation with eosinophilic and neutrophilic infiltration in Sephadex-treated rats.

ABSTRACT

Vitamin A is known to suppress the activity of the transcription factors, nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1), as do glucocorticoids. The possibility that vitamin A exerts various anti-inflammatory effects therefore seems likely. Sephadex beads were administered intravenously to anesthesized rats pretreated with a subcutaneous injection of vitamin A (3000, 10,000, or 30,000 IU/kg) or vehicle once daily for 3 days. After 16 h, the leukocyte differential, tumor necrosis factor (TNF)-alpha and eotaxin, and the DNA-binding activity of NF-kappaB were measured in bronchoalveolar lavage fluid (BALF). Additionally, lung histology was assessed using preparations stained with May-Giemsa stain. Sephadex beads caused histological granulomatous changes and eosinophilic and neutrophilic infiltration into the lung, and markedly increased cell counts of eosinophils and neutrophils, concentrations of TNF-alpha and eotaxin, and NF-kappaB binding to DNA in BALF. Vitamin A significantly inhibited all responses. Vitamin A may inhibit Sephadex-induced lung granulomatous formation, and eosinophilic and neutrophilic infiltration due to its suppression of TNF-alpha and eotaxin production, and NF-kappaB activation.